[Bf-viewport] OpenGL refactoring tasks

[Brecht Van Lommel]

On Fri, Dec 11, 2015 at 9:55 PM, Mike Erwin <significant.bit at gmail.com> wrote:
> For the GL_FLAT task do you mean the screen space derivatives in fragment
> stage? I think it's better handled earlier in the pipeline, by using flat
> interpolation and per-primitive normals. There needs to be some agreement
> between a flat shader and the mesh data feeding it to get the right results.

I think that if we can handle it in the fragment shader with
derivatives, that would be the simplest solution? What would be the
benefit of handling it earlier in the pipeline?